Insights on the Distribution of Mussels (Bivalvia: Unionida) in the Moro Creek Watershed, Arkansas.

The distribution of mussels is known from most major water bodies in the United States. Even so, the distribution of mussels in tributary systems of these water bodies is not well documented, especially in Arkansas. Moreover, there has never been a watershed-wide mussel survey in the Moro Creek watershed. During a recent study of fishes in this watershed, we observed 5 mussel species at 12 sites: Lampsilis hydiana (Louisiana Fatmucket), Sagittunio subrostratus (Pondmussel), Pyganodon grandis (Giant Floater), Toxolasma texasiense (Texas Lilliput), and Uniomerus declivis (Tapered Pondhorn). We observed a total of 34 live individuals and 8 fresh-dead specimens. The most abundant species documented was the Tapered Pondhorn, with18 (13 alive and 5 fresh-dead) individuals at 5 sites. The least abundant species was Giant Floater, with 1 individual at 1 site. There was evidence of recent recruitment in 2 species, Tapered Pondhorn (median total length [TL] = 71 mm; min-max = 28-99 mm), and Texas Lilliput (median TL = 21 mm; min-max = 13-40 mm). Future studies that target tributaries of the Ouachita, Red, and St. Francis drainages of Arkansas are likely to yield new distributional records for these species as well as others. [ABSTRACT FROM AUTHOR]